ACN OD’ OUN, 
Puate XXIX. 
(Fig. 56, 6, Mus. Cum. in Brit.) 
Anopon TrrANGuLARIS, Lea. (See Pl. XV.) The very 
short triangular specimen now figured will appear 
more characteristic of the species, and more 
suited to the name, than the one previously 
There is, however, no doubt about both 
specimens belonging to the same species. 
given. 

Species 115. (Fig. a, 6, Mus. Brit.) 
Anopon ciconiA. An. testd oblongo-subquadratd, tu- 
mida, valde inflata, magna, tenui, concentricé 
undulata, albida, epidermide sordidd induta, 
intus alba ; latere antico subquadrato, margine dor- 
sali recto, cuneato; medio subcontracto, wumbonibus 
prominentibus, ovatis, levigatis; latere postico 
producto, oblique biangulato, post angulum tri- 
gono, complanato, margine dorsali  subelevato, 
laterali declivi, ventrali surstum acclivi. 
Tue Stork Anopon. Shell oblong-subquadrate, tumid, 
much inflated, large, thin, concentrically undu- 
lated, rather white, covered with a mud-coloured 
epidermis, white within; anterior side subquadrate, 
dorsal margin straight, cuneate; middle a little 
contracted, with rather prominent, ovate, smooth 
umboes; posterior side produced, obliquely bian- 
gular, trigonal behind the angle, flat, with dorsal 
margin somewhat elevated, lateral sloped down- 
ward, ventral sloped upward. 

Govutp. MS. Mus. Brit. 
Hab. United States of North America. 
Much more square and obtuse at the extremities 
than Anodonta grandis. In the young state it is much 
flatter, and a little more pointed at the ends, but still 
has not the subtrigonal form of An. grandis. 

Species 116. (Mus. Brit.) 
ANODON VIGNONANUS. 
corrugatd, solida, fusca, intis subviridi ; latere 
antico brevissimo, rotundo, concentricé rugato ; 
An. testa elongata, compressa, 
medio complanato, divaricatim rugato, wmbonibus 
parvis, haud prominentibus, subviridibus, margine 
ventrali recto; latere postico producto, oblique 
biangulato, ad terminum truncato, ared postan- 
gulart angustd. 
Tue VicNon Anopoy. Shell elongated, compressed, 
corrugated, solid, brown, rather green within; 
anterior side very short, round, concentrically 
wrinkled; flattened in the middle, divergently 
wrinkled, umboes small, not prominent, rather 
green, ventral margin straight ; posterior side pro- 
duced, obliquely biangular, truncated at the end, 
postangular area narrow. 
Bern. MS. Mus. Brit. 
Hab, River Gaboon. 
The flattened area between the angles is more 
strongly plaited with divergent wrinkles than the other 
parts of the surface. 
June, 1870. 
